feat(engine): implement systematic debugging mode

.antigravity-plugin/manifest.json

@@ -1,7 +1,7 @@
 {
   "name": "canon",
   "displayName": "Canon Assistant Support for Antigravity",
-  "version": "0.64.0",
+  "version": "0.65.0",
   "description": "Canon provides semantic governance for AI-assisted engineering work: structured packets, governed evidence, approvals, lineage, project memory, and reusable delivery knowledge.",
   "author": {
     "name": "Apply The",

.claude-plugin/manifest.json

@@ -1,7 +1,7 @@
 {
   "name": "canon",
   "displayName": "Canon Assistant Support for Claude Code",
-  "version": "0.64.0",
+  "version": "0.65.0",
   "description": "Canon provides semantic governance for AI-assisted engineering work: structured packets, governed evidence, approvals, lineage, project memory, and reusable delivery knowledge.",
   "author": {
     "name": "Apply The",

.codex-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "canon",
   "displayName": "Canon Assistant Support for Codex",
-  "version": "0.64.0",
+  "version": "0.65.0",
   "description": "Canon provides semantic governance for AI-assisted engineering work: structured packets, governed evidence, approvals, lineage, project memory, and reusable delivery knowledge.",
   "author": {
     "name": "Apply The",

.cursor-plugin/manifest.json

@@ -1,7 +1,7 @@
 {
   "name": "canon",
   "displayName": "Canon Assistant Support for Cursor",
-  "version": "0.64.0",
+  "version": "0.65.0",
   "description": "Canon provides semantic governance for AI-assisted engineering work: structured packets, governed evidence, approvals, lineage, project memory, and reusable delivery knowledge.",
   "author": {
     "name": "Apply The",

.github/workflows/quality.yml

@@ -29,7 +29,7 @@ jobs:
       - uses: taiki-e/install-action@v2
         with:
           tool: cargo-llvm-cov
-      - run: cargo llvm-cov --workspace --all-features --lcov --output-path lcov.info
+      - run: bash scripts/coverage.sh
       - name: SonarQube Scan
         uses: SonarSource/sonarqube-scan-action@v6.0.0
         env:

.gitignore

@@ -1,3 +1,6 @@
+# Ignore the homebrew-canon directory, which may contain generated files or dependencies related to the project.
+/homebrew-canon
+
 # Generated by Cargo
 # will have compiled files and executables
 debug

.specify/feature.json

@@ -1,3 +1,3 @@
 {
-  "feature_directory": "specs/065-reasoning-posture-v2"
+  "feature_directory": "specs/067-systematic-debugging"
 }

AGENTS.md

@@ -1,6 +1,6 @@
 # Canon Development Guidelines
 
-Auto-generated from all feature plans. Last updated: 2026-06-01
+Auto-generated from all feature plans. Last updated: 2026-06-03
 
 ## Governing Constitution
 
@@ -13,6 +13,7 @@ Auto-generated from all feature plans. Last updated: 2026-06-01
 ## Active Technologies
 - Rust 1.96.0, Edition 2024; Markdown planning artifacts + workspace crates `canon-cli` and `canon-engine`; existing `clap`, `serde`, `serde_json`, `serde_yaml`, and `tracing`; planned `ratatui` plus `crossterm` for the full-screen init UI; existing `assert_cmd` and `tempfile` for CLI validation (063-interactive-init-ui)
 - `.canon/` runtime scaffolding in the target workspace; planning and contract artifacts under `specs/063-interactive-init-ui/` (063-interactive-init-ui)
+- Rust 1.96.0, Edition 2024 + clap, serde, serde_json, serde_yaml, tracing, thiserror (067-systematic-debugging)
 
 - Rust 1.96.0, Edition 2024
 - `clap`, `serde`, `serde_json`, `serde_yaml`, `toml`
@@ -74,9 +75,9 @@ Before 1.0.0, breaking changes MAY occur in minor versions.
 - `specs/001-canon-spec/decision-log.md`
 
 ## Recent Changes
+- 067-systematic-debugging: Added Rust 1.96.0, Edition 2024 + clap, serde, serde_json, serde_yaml, tracing, thiserror
 - 063-interactive-init-ui: Added Rust 1.96.0, Edition 2024; Markdown planning artifacts + workspace crates `canon-cli` and `canon-engine`; existing `clap`, `serde`, `serde_json`, `serde_yaml`, and `tracing`; planned `ratatui` plus `crossterm` for the full-screen init UI; existing `assert_cmd` and `tempfile` for CLI validation
 - 062-clarify-run-refinement: Added Rust 1.96.0, Edition 2024; Markdown documentation and templates; existing Spec Kit shell helpers + workspace crates `canon-engine`, `canon-cli`, `canon-adapters`; existing `clap`, `serde`, `serde_json`, `serde_yaml`, `toml`, `thiserror`, `tracing`, `uuid`, and `time`; repo-local methods, templates, and skill-source documents
-- 061-skill-runtime-contracts: Added Bash 5.x (macOS/Linux), PowerShell 7.x (cross-platform) + `jq` (JSON validation), `canon` CLI (version
 
 <!-- MANUAL ADDITIONS START -->
 ## Codex Skills Frontend

CHANGELOG.md

@@ -15,10 +15,19 @@ The repository history contains no release bumps for `0.10.0`, `0.13.0`,
 `0.16.0`, or `0.17.0`, so adjacent feature slices are rolled into the next
 recorded workspace version.
 
-## [Upcoming]
+## [0.65.0] - 2026-06-03
 
-Planning notes for the next release line are not fixed yet. This section will
-be updated once new work is scoped.
+Delivered specs:
+
+- `specs/067-systematic-debugging/`
+
+Highlights:
+
+- Added a first-class `debugging` mode for systematic defect resolution, emphasizing root-cause isolation and red-to-green test transitions.
+- Enforced required artifacts for the `debugging` mode: `01-context`, `02-reproduction`, `03-root-cause`, `04-fix-decision`, and `05-verification`.
+- Integrated `debugging` mode into the governance surface and CLI contracts as a recommendation-only, green-zone workflow.
+- Updated docs, README, and CLI references to include `debugging`.
+- Bumped workspace version to `0.65.0`.
 
 ## [0.64.0] - 2026-06-02
 

Cargo.toml

@@ -21,7 +21,7 @@ resolver = "2"
 edition = "2024"
 license = "MIT"
 rust-version = "1.96.0"
-version = "0.64.0"
+version = "0.65.0"
 
 [workspace.dependencies]
 assert_cmd = "2"

README.md

@@ -60,7 +60,7 @@ These are the commands you'll actually use every day:
 
 | Command | What it does |
 |---|---|
-| `canon run` | Start a new governed session with explicit boundaries. |
+| `canon run` | Start a new governed session with explicit boundaries. Available modes include `requirements`, `architecture`, `debugging`, `change`, `incident`, and more. |
 | `canon status` | See exactly what the agent is doing right now. |
 | `canon inspect` | Review generated evidence and artifacts. |
 | `canon approve` | Unblock a session that hit a governance gate. |

assistant/plugin-metadata.json

@@ -1,7 +1,7 @@
 {
   "name": "canon",
   "displayName": "Canon Assistant Support",
-  "version": "0.64.0",
+  "version": "0.65.0",
   "description": "Governed packet runtime for AI-assisted engineering work",
   "author": {
     "name": "Apply The",

crates/canon-engine/src/artifacts/contract.rs

@@ -57,6 +57,7 @@ pub fn contract_for_mode(mode: Mode) -> ArtifactContract {
         Mode::Migration => operations::migration(),
         Mode::DomainLanguage => domain::domain_language(),
         Mode::DomainModel => domain::domain_model(),
+        Mode::Debugging => delivery::debugging(),
     };
 
     build_contract(files)

crates/canon-engine/src/artifacts/contract/delivery.rs

@@ -41,6 +41,13 @@ const REGRESSION_EVIDENCE_MD: &str = "regression-evidence.md";
 const CONTRACT_DRIFT_CHECK_MD: &str = "contract-drift-check.md";
 const NO_FEATURE_ADDITION_MD: &str = "no-feature-addition.md";
 
+// Debugging
+const CONTEXT_MAP_MD: &str = "context-map.md";
+const REPRODUCTION_HARNESS_MD: &str = "reproduction-harness.md";
+const ROOT_CAUSE_ISOLATION_MD: &str = "root-cause-isolation.md";
+const FIX_APPLICATION_MD: &str = "fix-application.md";
+const VERIFICATION_SUMMARY_MD: &str = "verification-summary.md";
+
 // ── Mode contracts ────────────────────────────────────────────────────────────
 
 /// Returns the artifact requirements for the [`Backlog`](crate::domain::mode::Mode::Backlog) mode.
@@ -223,6 +230,37 @@ pub(super) fn refactor() -> Vec<ArtifactRequirement> {
     ]
 }
 
+/// Returns the artifact requirements for the [`Debugging`](crate::domain::mode::Mode::Debugging) mode.
+pub(super) fn debugging() -> Vec<ArtifactRequirement> {
+    vec![
+        requirement(
+            CONTEXT_MAP_MD,
+            &[SUMMARY, "Context Map", "Defect Description", "Stakeholder Impact"],
+            &[GateKind::Exploration, GateKind::Risk],
+        ),
+        requirement(
+            REPRODUCTION_HARNESS_MD,
+            &[SUMMARY, "Reproduction Harness", "Red State Verification"],
+            &[GateKind::Reproduction, GateKind::TestDrivenDevelopment],
+        ),
+        requirement(
+            ROOT_CAUSE_ISOLATION_MD,
+            &[SUMMARY, "Root Cause Isolation", "Fault Chain", "Isolation Proof"],
+            &[GateKind::RootCause, GateKind::Architecture],
+        ),
+        requirement(
+            FIX_APPLICATION_MD,
+            &[SUMMARY, "Fix Application", "Bounded Changes", "Invariant Preservation"],
+            &[GateKind::RootCause, GateKind::ReleaseReadiness],
+        ),
+        requirement(
+            VERIFICATION_SUMMARY_MD,
+            &[SUMMARY, "Verification Summary", "Green State", "No Regression Evidence"],
+            &[GateKind::ReleaseReadiness, GateKind::TestDrivenDevelopment],
+        ),
+    ]
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/canon-engine/src/artifacts/markdown.rs

@@ -209,8 +209,9 @@ pub use authoring::{
     render_requirements_artifact_from_evidence, render_system_shaping_artifact,
 };
 pub use delivery::{
-    render_backlog_artifact, render_change_artifact, render_implementation_artifact,
-    render_incident_artifact, render_migration_artifact, render_refactor_artifact,
+    render_backlog_artifact, render_change_artifact, render_debugging_artifact,
+    render_implementation_artifact, render_incident_artifact, render_migration_artifact,
+    render_refactor_artifact,
 };
 pub use domain::{render_domain_language_artifact, render_domain_model_artifact};
 pub use governance::{